The present invention relates to wire guides used for percutaneous placement of catheters and other medical devices in the vasculature of a patient.
A wire guide can be used for percutaneous placement of a catheter into a vascular system. The wire guide has a proximal end that is held by a physician and a distal end that is inserted into the vascular system. In use a physician inserts an introducer needle with the wire guide into a vessel, e.g., a brachial vein, a cephalic vein. The wire guide is introduced through the introducer needle into the vessel to a part of the vascular anatomy at which the physician is performing an interventional or diagnostic procedure. The needle is then withdrawn over the wire guide and a catheter placed over the wire guide. A physician holds a proximal portion of a catheter as a distal portion of the catheter is inserted over the wire guide. The physician may use one of many types of catheters or medical devices with the wire guide to perform the procedure, such as a peripherally inserted central catheter (PICC) line.
When a wire guide is percutaneously introduced into a vessel of the patient, the physician verifies that a suitable portion of the catheter or other medical device will be inserted over the wire guide to a precise location in the vasculature of the patient. If a relatively large portion of the catheter remains outside of the patient's body, the catheter may be caught on outside objects, affecting the placement of the catheter and causing the patient to experience discomfort. Typically, in order to limit the patient's discomfort, the wire guide in the vessel of the patient is extracted from the vessel with a clamp attached to the proximal portion of the wire guide remaining outside of the patient's body. The catheter is then placed side by side next to the wire guide and the proper amount of a distal portion of the catheter is cut or trimmed away. The trimmed distal portion of the catheter is cut according to marks on the wire guide which indicate a length of the wire guide inserted into the patient. The trimmed catheter may then be inserted into the patient over the guide wire to the location in the vasculature or by using a stiffening wire inside the catheter and advancing the catheter without use of the wire guide. This procedure is generally time consuming because it requires the physician insert the wire guide, withdraw the wire guide, cut the distal portion of the catheter and insert the catheter into the patient, although it ensures that only a small proximal portion of the catheter will be left outside of the patient's body during the interventional procedure.
Another method has been developed to insert a PICC over a wire guide into a patient, wherein a relatively longer length wire guide is used. The wire guide has marks on the distal end at 60 centimeter (cm) that allow the user to determine the length of the catheter that must be trimmed by looking at the marks that are remaining outside of the patient's body. However, most of the materials used for these PICC lines include silicone and urethane, which may not allow the catheter to be easily advanced over the wire guide due to friction resistance. In addition, the utilization of these PICC line materials can lengthen the time of this procedure, causing undesired difficulty and discomfort.
Therefore, there is a need for an apparatus and a method that enables a user to quickly and easily advance a catheter over a wire guide, assisting in the determination of where the catheter should be trimmed with relatively low resistance.